A new large-celled species of Plagiochila (Plagiochilaceae, Hepaticae) from the southern flank of the Russian Far East

Abstract

A new species of Plagiochila is described from cool-temperate Ussuri taiga zone in the Russian Far East using integrative morphological and molecular-genetic ap proach. Plagiochila sichotensis Bakalin et Vilnet sp. nov. (sect. Plagiochila) is charac terized by totally entire leaves, relatively small size and, particularly, very large midleaf cells reaching 40-60 µm wide in the leaf middle. The latter feature distin guishes the new species from all known taxa of the genus and, among regional ta xa, somewhat similar to the not evolutionary related Mylia. This epixylous taxon seems to be confined in its distribution to the low to middle elevation of moun tains in the southern Sikhote-Alin Mts. The description, illustrations and dis cus sion on the new species are provided.